1. Field of the Invention
The present invention relates to a self-illuminant delineator and a delineator system by use of a plurality of self-illuminant delineators each of which flickers a plurality of light-emitting diodes utilizing solar cells as power supply to arise drivers' attention.
2. Prior Art
Self-illuminant delineators which are installed to indicate road shoulders and to guide drivers' eyes at zigzag courses are powered by commercial power supply or dry batteries. When they are used on roads where it is impossible to use commercial power supply, they require troublesome maintenance such as periodical exchange of dry batteries. To solve this problem, a self-illuminant delineator which operates on solar cells has been proposed (refer to Japanese Utility Model Provisional Publication No. 52-95389, Japanese Patent Provisional Publication No. 52-89081 and Japanese Patent Provisional Publication No. 52-89082).
The self-illuminant delineator uses solar cells as power supply for light-emitting diodes and as a means for detecting the brightness of the surrounding area so that the detected signals can turn on or off the light-emiting diodes. That is, the output voltage of the solar cells is converted into a signal. More particularly, when the output voltage of the solar cells is high in the daytime, the output is charged in a battery. When the output voltage drops below a certain level after sunset, the battery is discharged so that the light-emitting diodes light or flicker (hereafter "flicker" is referred to). When the output voltage of the solar cells increases above the certain level after sunrise, battery discharge stops and the output of the solar cells is charged in the battery.
In practice, a plurality of the self-illuminating delineators are usually installed at equal intervals where roads are winding or where traffic accidents occur frequently. These delineators have the following defects. If one of the self-illuminant delineators is installed under the shadow of an obstacle, such as a tree, only the delineator begins to flicker. Even if the flickering period of each delineator is set at a certain value, all the delineators do not have the same cycle. Thus, the delineators flicker at random cycles when viewed the entire line-up. As a result, the delineators cannot provide proper traffic information and drivers are perplexed.